Solenoid mechanism



Nov. 28, 1939. w. H. GILLE I SOLENOID MECHANISM Filed Sept. 9, 1955Patented Nov. 28, 1939 UNITED STATES PATENT OFFICE SOLENOID IWECHANISMApplication September 9, 1935, Serial No.'39,701

Claims. (01. 175-338) My invention relates to a solenoid mechanism, andmore particularly to one designed to operate a valve and to becontrolled by a thermostat.

Where a solenoid mechanism is to be controlled 5 by a thermostat, it hasbeen proposed to incorporate with said solenoid mechanism a switch whichis moved to closed position upon the solenoid winding being energizedand which switch serves to establish a holding circuit for the oper- Iation of the solenoid. Where such a mechanism was to be operated bydirect current, no particular difliculties were encountered. However,when such a mechanism was to be operated by alternating current it hasbeen almost impossible to 15 operate an associated switch by the actionof the solenoid associated with the mechanism due to the excessivevibration in the switch caused by the variation of the flux produced bythe alternating current. As a result, it has been necessary to employ aseparate relay to establish the holding circuit.

An object of the present invention is to provide a solenoid mechanismdesigned for operation with alternating current in which a switch 25 isincorporated therewith and is operated by the solenoid and in whichvibration of said switch is substantially eliminated.

A further object of this invention is to provide a solenoid mechanismfor alternating current operation embodying a switch therewith, in whichthe solenoid core is contained in one sealed compartment and in whichthe switch is contained in another such compartment.

A further object of this invention is to provide a solenoid actuatedmechanism for alternating current operation having a switch incorporatedtherewith and actuated by the solenoid in which a single shading meansis effective to eliminate vibration of both-said core and said switch.

Other objects of the invention will be apparent from the accompanyingspecification, claims and drawing, in which:

Figure 1 is a sectional view of my mechanism applied to the operation ofa valve with a schematic showing of the thermostatic controlling means,and in which Figure 2 is a section on the line 22 of Fig-- ure 1, withportions broken away.

Referring to Figure 1 in the drawing, the valve portion of my device isgenerally indicated by the reference numeral III. This portion comprisesa valve body ll having inlet and outlet connections l2 and I3. Theinterior of said valve body is separated by a transverse wall 14 havingan aperture therein in which is mounted a plug l5. This plug l5 has anaperture 19 therethrough which is flared at its upper end to provide avalve seat IT. The valve is constituted by the lower end I8 of a core I9of a solenoid actuating mechanism. The solenoid actuating mechanism ishoused in a casing 20. This casing has attached at its lower end anannular member 2| of magnetic material, which is connected to the valvebody II by a screw thimble connection through the collar 3. The member2| is provided at its 10 outer extremity with a downwardly directedflange having a recessed portion 22 in which is mounted a spring disc 23through. a retaining ring 24. The springdisc 23 is provided withapertures 25 to make the same more resilient and is provided along itsinner portion with an upturned edge 26.

The housing proper comprises a cylindrical member 21 of magneticmaterial and upper and lower circular plates 28 and 29. Members 21 andg0 29 are of magnetic material. The housing is retained in position byany suitable fastening means such as studs 30, which arescrew-threadedly engaged with the lower plate 29.

Mounted within the casing is a solenoid coil 3|. The terminal conductorsof said coil are indicated by the reference numerals 32 and 33,respectively.

A disc 35 of insulating material is secured to the casing and serves toseparate the switch containing portion of the housing from the restthereof. Attached to said disc of insulating material is a ring 36 ofmagnetic material. This ring has its upper edge turned over to form asupporting flange therefor. This flange is provided with three outwardlyextending equally spaced projections 19, 80 and 8|, as shown in Figure2. The flange is secured to disc 35 by any suitable fastening means suchas rivets 38.

Mounted within the solenoid core is a coreguiding sleeve 39 of suitablenon-magnetic material such as brass. This sleeve is fastened at itslower end to an upturned flange of the annular member 2| and at itsupper end to the ring 36. The connection at the lower end is made 5 in afluid tight manner by any suitable means, shown for purposes ofillustration, as soldering.

Attached to the sleeve 39 at its upper end is a core stop 40 comprisinga center pin member 4| of magnetic material and a surrounding sleevemember 42 of non-magnetic material of relatively high conductivity.Sleeve member 42 is secured to the sleeve 39 in a fluid tight mannersuch as by soldering and pin 4| is similarly secured to ring 42. Sleeve42 is provided with a lower conical extremity 43. The pin 4| is providedwith a head 44 at its lower end, said head-having a conical portion 45at the lower extremity thereof. It will be seen that the guiding sleeve39 and the stop 4|] form with the casing a fluid-tight compartmentwithin which the core operates.

The core I9 comprises a body portion 46 having a reduced portion 88 atone extremity constituting the valve. At the juncture of the saidreduced portion with the main body portion of the core, the core isflared outwardly as at 41 to provide a conical shoulder to cooperatewith the upturned edge 26 of spring retainer 23. At its upper end thecore is provided with a recess having two conical portions 48 and 49 ofdifferent slope. An aperture 58 extends through said core and isconnected with the conical recess through a circular disc 51 of magneticmaterial.

a second aperture at right angles therewith. The slope of conicalportion 48 corresponds to that of portion 43 of the stop 40 and theslope of conical portion 49 corresponds to that of conical portion 45 ofpin 4|. The pin 4| serves as the stop proper for the core while thesleeve 42 serves to guide the core into engagement with the stop and isslightly spaced from the core when it is in engagement with pin 4|. Theapertures 58 and 5| serve to prevent any dashpot action by permittingthe ready escape of air in the core recess as the core moves intoengagement with the stop 4t.

' Mounted on the insulating disc 35 is a plate 52 of magnetic materialin the form of an incomplete annulus. Referring to Figure 2, this plateis provided with three inwardly extending projections 82, 83 and 84,which are equally spaced from each other and from projections 19, 80 and8| of sleeve 36. Also mounted on said insulating disc is a switch arm 53through a bolt 54 and an insulating washer 55. Switch arm 53 isresilient in character and has attached thereto This disc is separatedfrom the switch arm by an insulating washer 58 and is held thereto byany suitable fastening means such as a rivet 59. The switch arm 53 isprovided at one end with a contact 60 which is adapted to cooperate witha fixed contact 6| secured to the insulating disc 35 by suitablefastening means 62. Contacts 68 and 6| are so spaced that uponenergization of the coil armature 51 will move switch arm 60 downwardlysufficiently to cause engagement of these contacts. Attached to saidswitch arm through the fastenirg means 54 is a stop 63 which limits theoutward movement of said switch arm. Attached to said lower end of saidfastening means 54 is a terminal connection 65 and attached to the lowerend of fastening member 62 is a similar terminal member 66. Terminalconductor 32 of the coil 3| is shown as connected to terminal 66 but itwill be understood that this is for purposes-of illustration only andthat said conductor may be connected to any suitable terminal such asone located on the exterior of the casing.

A thermostat 68 comprises a bimetallic element 69 to which is attached acontact arm 18 having contacts. 1| and 12 adapted to engage withcontacts 13 and 14, respectively. Contacts 12 and 14 are less widelyspaced from each other than contacts 1| and 13 so that upon contact arm16 moving in the direction of contacts 12 and 14, contacts 12 and 14will be brought into engagement before contacts 1| and 13.

A transformer 16 furnishes low voltage alternating current for theoperation of my valve. This transformer comprises a line voltage primary16 and a low voltage secondary 11. The line voltage primary is connectedto line wires 18 which are, in turn, connected to a source ofalternating current.

Upon the bimetallic element being subjected to a change in temperaturewhich causes it to move contact arm 18 in the direction of contacts 13and 14, contacts 12 and 14 will first be brought into engagement. Thebringing into engagement of these contacts does not, however, establishan energizing circuit. If the change in temperature continues with theresultant further movement of arm 18 in the direction of,con tacts 13and 14, contacts 1| and 13 will be brought into engagement. Upon suchaction taking place the following energizing circuit will be establishedthrough the solenoid coil 3| From secondary 11, through conductor 88,contacts 14 and 12, contacts 1| and 13, conductor 86, terminal 66,conductor 32, the relay coil, conductor 33 and conductor 82 back to thesecondary 11. This energization of the solenoid coil 3| causes a flow ofmagnetic flux through two different paths. One of these paths comprisesthe core |9 magnetic ring 36, the air gap between said ring and armature51, armature 51, the air gap between the armature and plate 52, plate52, the cylindrical housing member 21 and the lower housing plate 29back to core l9. The second flux path comprises core l9, the magneticpin member 4|, the air gap between said pin member and armature 51,armature 51, the air gap between the armature and plate 52, plate 52,the cylindrical housing member 21 and lower plate 29 back to core IS.The second flux path is influenced by the presence of ring 42 ofconductive non-magnetic material which acts as a shading ring. Theresult is that the flow of flux through the said second path lags theflow of flux in the first path by substantially 90. The result will bethat both core member l9 and armature 51 are subjected to flux flowingin two different fiux paths, the flux of which has a zero value atdifferent times. Thus, the core l9 and the armature 51 will always besubjected to some fiux.

Since in an electromagnetic arrangement of this kind, the movablemagnetic members tend to assume the position which provides a magneticpath of the lowest possible reluctance, the core |9 will be urgedupwardly into engagement with the stop 40 and the armature 51 will beurged downwardly in a direction such as to cause engagement of contacts68 and 6|. Due to the relatively small movement required of the armature51 to effect engagement of these contacts, such engagement will be madebefore the solenoid has raised appreciably.

The moving into engagement of contacts 68 and 6| results in thefollowing holding circuit being established: From secondary 11, throughconductor 88, contacts 14 and 12, bimetallic element 68, conductor 85,terminal 65, switch arm 53, contacts 68 and 6|, terminal 66, conductor32, solenoid coil 3|, conductor 33, conductor 82, back to the secondary11. It will be noted that this new holding circuit is independent of theengagement of contacts 1| and 13 so that even though contact arm mightmove slightly to the right causing the separation of contacts 1| and 13,the solenoid would remain energized. Since the holding circuit isestablished by the engagement of contacts 60 and 6| before the core hasraised appreciably, a slight vibration of contact arm 10 is preventedfrom periodically moving the core valve member slightly off its seat.This is of especial advantage where the valve is employed to control theflow of gas to a burner, since if a slight vibration of contact arm 10were allowed to raise and drop the core off its seat, puffs of gas wouldbe admitted to the burner, which might lead to an explosion.

Due to the presence of the three projections 19, 80 and 8| of the flangeof ring 36 and the three projections 82, 83 and 84 of plate 52 withwhich the armature is in contact, the armature will be held firmlyagainst the flange of ring 36 and plate 52 at these points. This resultsin a three-point holding action which insures against vibration of thearmature due to an uneven engagement with the ring or plate.

When the core is in its uppermost position, the conical shoulder 41 isin engagement with the upturned portion '76 of the spring disc 23 and isurged downwardly by said spring disc. Thus, upon deenergization of thesolenoid, the spring disc 23 serves to insure the return of the core toits lowermost position. In this way there is an assurance that the corewill not be held in its uppermost position by reason of any stickingbetween the pin 44 and the conical recess 49.

Since both the armature and the core are in two different flux paths;the fluxes of which are displaced in phase, the flux acting on thesemembers will never have a zero value. As a result of this, there is notthe tendency to chatter which is usually present with solenoid apparatusof this type. This feature coupled with the positive stops for the coreand armature insure a quiet operation of the valve and switch.

It will be seen from the foregoing description that I have provided asolenoid mechanism having a switch associated therewith and actuated bythe solenoid which is adapted for operation with alternating currentwithout the chattering which hitherto prevented the use of such devices.

While I have shown a specific embodiment oi my invention, it will geunderstood that this is for purposes of illustration only and that myinvention is limited only by the scope of the appended claims.

I claim as my invention:

1. An electromagnetic actuatingmeans designed for operation withalternating current comprising a winding, a movable magnetic core, astop for said core, an armature adjacent said stop, said armature andsaid core being moved in the direction of said stop upon energization ofsaid winding, said stop comprising a member of mag netic materialsurrounded by a ring of conducting non-magnetic material which extendsfrom the upper to the lower surface of said stop and one end of both thesaid member and the said ring extending in a common plane forcooperation with said armature, the said stop acting to shade a portionof the flux through both said core and said armature to preventvibration of either said core or said armature.

2. In an actuating mechanism designed for use with alternating current,a solenoid coil, a core of magnetic material movable within said coil,an armature adjacent said coil, and means located adjacent said coil andbetween said armature and core comprising a shading ring of conductivenonmagnetic material and members of magnetic material completelyseparated by said shading ring, each of said members having a portionclosely adjacent to each of said armature and said core, so that theflux flowing through the core, the armature, 'and said members consistsof a shaded and an unshaded component.

3. In an actuating mechanism designed for use with alternating current,a solenoid coil, a

core of magnetic material movable within saidcoil, an armature adjacentone end of said coil, means located within the end of the coil adjacentto said armature comprising concentric spaced members of magneticmaterial and a shading ring of conductive non-magnetic materialsurrounding one ofsaid spaced members, said means being located betweensaid armature and said core and said magnetic members being magneticallyjoined only by said armature and said core so that the flux flowingthrough both the core and armature consists of a shaded and an unshadedcomponent.

4. In combination, a solenoid actuating mechanism adapted to be operatedby alternating current, said solenoid actuating mechanism comprising asolenoid coil, a magnetic core slidably mounted therein, said core beingurged downwardlyby gravity when said coil is deenergized and being movedupwardly upon energization of said coil, a stop to limit the upwardmovement of said core, said stop comprising a central pin of magneticmaterial surrounded by a ring of non-magnetic conducting material, saidpin and said ring extending from the upper surface to the lower surfaceof said stop and having their upper surfaces in a common plane, anarmature member adapted to be moved into proximity with the upper end ofsaid stop, said ring serving to subject a portion of the flux flow inboth said core and said armature to a shading action to preventvibration of either said core or said armature.

5. In the combination described comprising, a solenoid coil, anon-magnetic sleeve extending within said coil, a solenoid core withinsaid sleeve for operating a valve, a stop for limiting movement of saidcore in one direction and to which said sleeve is secured, said stopcomprising a member of magnetic material and a surrounding member ofnon-magnetic conducting material, a shell of magnetic material aroundsaid coil, a magnetic member above said coil and extending inwardly fromsaid shell, an inner member of magnetic material spaced from andsurrounding said stop and having an outer surface extending within butspaced from the member above said coil to form an air gap therebetween,an armature for operating a switch actuated by said coil and extendingover said air gap, said inner member and said stop, a magneticelement'beneath saidcoil and constituting a magnetic path of lowreluctance between said shell and said core, the said inner memberconstituting a path for a portion of the flux through said armature andsaid core, and the said stop constituting a parallel shaded path foranother portion of the flux through said armature and said core.

WILLIS H. GILLE.

